DB Record Distribution Statistics report
This report contains statistics about database record distribution.
The following information is included in the report:
- Statistics about the locations of HDAM or PHDAM root segment
- How long and how the HDAM or PHDAM RAP chains are distributed
- The number of dependents stored in the same block or CI as their root segment
- The number of dependents stored in the same block or CI as their segment code, and the percentage of each that is included in the root block.
This report is produced unless you specify DBDIST=NO on the REPORT statement, or INCORE=NO on the OPTION statement. This report is available only for HD databases. This report provides information about the data set. If the database is HALDB, this report provides information about each partition.
For report examples, see Report example.
For
report field descriptions, see the following subsections:
Report example
The following figures show an example of the report.
IMS HIGH PERFORMANCE POINTER CHECKER FOR z/OS "DB RECORD DISTRIBUTION STATISTICS REPORT" PAGE: 1
5655-U09 DATE: 05/09/2020 TIME: 01.10.41 FABPMAIN - V3.R1
DBNAME: TPFOH1 DB#: 001 PARTNAME: TPFOH1A PART ID: 00001 REORG#: 00002 DSG#: A DDNAME: TPFOH1AA
DSNAME: TESTDS.PUBLIC.SAMPLE.TPFOH1.A00001
TOTAL NUMBER OF SEGMENTS (ROOTS + DEPENDENTS) IN THE DATA SET = 66976
MAXIMUM ROOTS PER BLOCK = 7
BLOCKS WITHOUT ROOT SEGMENTS IN RAA = 1766
DISTRIBUTION OF ROOT SEGMENTS (HDAM/PHDAM ONLY)
-----------------------------------------------
NUMBER OF
LOCATION ROOTS PERCENTAGE
---------------------- ---------- ----------
HOME BLOCK - ( 11- ) 0 0.0 %
HOME BLOCK - 10 0 0.0 %
HOME BLOCK - 9 0 0.0 %
HOME BLOCK - 8 0 0.0 %
HOME BLOCK - 7 0 0.0 %
HOME BLOCK - 6 0 0.0 %
HOME BLOCK - 5 0 0.0 %
HOME BLOCK - 4 0 0.0 %
HOME BLOCK - 3 3 0.0 %
HOME BLOCK - 2 7 0.1 %
HOME BLOCK - 1 118 1.1 %
HOME BLOCK 2,500 22.7 %
HOME BLOCK + 1 0 0.0 %
HOME BLOCK + 2 1 0.0 %
HOME BLOCK + 3 2 0.0 %
HOME BLOCK + 4 1 0.0 %
HOME BLOCK + 5 0 0.0 %
HOME BLOCK + 6 0 0.0 %
HOME BLOCK + 7 0 0.0 %
HOME BLOCK + 8 0 0.0 %
HOME BLOCK + 9 0 0.0 %
HOME BLOCK + 10 1 0.0 %
HOME BLOCK + ( 11- ) 1,768 16.1 %
OVERFLOW 6,599 60.0 %
---------------------- ---------- ----------
TOTAL 11,000 100.0 %
TOTAL NUMBER OF ROOT SEGMENTS = 11000 100.0 %
NUMBER OF ROOT SEGMENTS IN HOME BLOCKS = 2500 22.7 %
NUMBER OF ROOT SEGMENTS NOT IN HOME BLOCKS = 8500 77.3 %
IMS HIGH PERFORMANCE POINTER CHECKER FOR z/OS "DB RECORD DISTRIBUTION STATISTICS REPORT" PAGE: 2
5655-U09 DATE: 05/09/2020 TIME: 01.10.41 FABPMAIN - V3.R1
DBNAME: TPFOH1 DB#: 001 PARTNAME: TPFOH1A PART ID: 00001 REORG#: 00002 DSG#: A DDNAME: TPFOH1AA
DSNAME: TESTDS.PUBLIC.SAMPLE.TPFOH1.A00001
DISTRIBUTION OF RAP CHAIN LENGTHS (HDAM/PHDAM ONLY)
---------------------------------------------------
CHAIN NUMBER NUMBER PERCENTAGE CUMULATIVE
LENGTH OF RAPS OF ROOTS OF ROOTS PERCENTAGE
------ --------- --------- ---------- ----------
1 978 978 8.9 % 8.9 %
2 1,148 2,296 20.9 % 29.8 %
3 899 2,697 24.5 % 54.3 %
4 575 2,300 20.9 % 75.2 %
5 298 1,490 13.5 % 88.7 %
6 134 804 7.3 % 96.0 %
7 36 252 2.3 % 98.3 %
8 15 120 1.1 % 99.4 %
9 7 63 0.6 % 100.0 %
10 0 0 0.0 % 100.0 %
11 0 0 0.0 % 100.0 %
12 0 0 0.0 % 100.0 %
13 0 0 0.0 % 100.0 %
14 0 0 0.0 % 100.0 %
15+ 0 0 0.0 % 100.0 %
------ --------- --------- ---------- ----------
TOTAL 4,090 11,000 100.0 %
RAPS USED (ACTIVE) = 4,090 90.9 %
RAPS NOT USED = 410 9.1 %
TOTAL RAPS = 4,500 100.0 %
MAXIMUM ROOTS PER RAP = 9
AVERAGE ROOTS PER ACTIVE RAP = 2.7
AVERAGE ROOTS PER TOTAL RAP = 2.4
NUMBER OF SYNONYM CHAINS = 3,112
AVERAGE ROOTS PER SYNONYM CHAIN = 3.2IMS HIGH PERFORMANCE POINTER CHECKER FOR z/OS "DB RECORD DISTRIBUTION STATISTICS REPORT" PAGE: 3
5655-U09 DATE: 05/09/2020 TIME: 01.10.41 FABPMAIN - V3.R1
DBNAME: TPFOH1 DB#: 001 PARTNAME: TPFOH1A PART ID: 00001 REORG#: 00002 DSG#: A DDNAME: TPFOH1AA
DSNAME: TESTDS.PUBLIC.SAMPLE.TPFOH1.A00001
SUMMARY OF DEPENDENT SEGMENTS DISTRIBUTION
------------------------------------------
NUMBER OF DEPENDENTS IN AS SAME BLOCK AS ROOT = 3745
AVERAGE DEPS IN AS SAME BLOCK AS ROOT PER ROOT = 2.1
NUMBER OF DEPENDENTS IN THE DIFFERENT BLOCK TO ROOT = 52231
DISTRIBUTION OF DEPENDENT SEGMENTS IN ROOT BLOCK
------------------------------------------------
-------------------------------------------------------------------------------------
#ROOTS WITH 00 DEPS = 9246 #ROOTS WITH 12 DEPS = 0
#ROOTS WITH 01 DEPS = 403 #ROOTS WITH 13 DEPS = 0
#ROOTS WITH 02 DEPS = 711 #ROOTS WITH 14 DEPS = 0
#ROOTS WITH 03 DEPS = 640 #ROOTS WITH 15 DEPS = 0
#ROOTS WITH 04 DEPS = 0 #ROOTS WITH 16 DEPS = 0
#ROOTS WITH 05 DEPS = 0 #ROOTS WITH 17 DEPS = 0
#ROOTS WITH 06 DEPS = 0 #ROOTS WITH 18 DEPS = 0
#ROOTS WITH 07 DEPS = 0 #ROOTS WITH 19 DEPS = 0
#ROOTS WITH 08 DEPS = 0 #ROOTS WITH 20 DEPS = 0
#ROOTS WITH 09 DEPS = 0 #ROOTS WITH 21 DEPS = 0
#ROOTS WITH 10 DEPS = 0 #ROOTS WITH 22 DEPS = 0
#ROOTS WITH 11 DEPS = 0 #ROOTS WITH 23 DEPS = 0
#ROOTS WITH 24+ DEPS = 0
-------------------------------------------------------------------------------------
#ROOTS IN THE DATA SET = 11000
DISTRIBUTION OF DEPENDENT SEGMENTS BY SEGMENT CODE
--------------------------------------------------
SEGMENT CODE #DEPS IN #DEPS IN PERCENTAGE SEGMENT CODE #DEPS IN #DEPS IN PERCENTAGE
ROOT BLOCK ALL BLOCKS (ROOT/ALL) ROOT BLOCK ALL BLOCKS (ROOT/ALL)
------------- ---------- ---------- ---------- ------------- ---------- ---------- ----------
(SEGCODE 02 ) 30 900 3.33 (SEGCODE 13 ) N / A N / A N / A
(SEGCODE 03 ) 0 0 .00 (SEGCODE 14 ) N / A N / A N / A
(SEGCODE 04 ) 1735 16421 10.56 (SEGCODE 15 ) N / A N / A N / A
(SEGCODE 05 ) 1557 16422 9.48 (SEGCODE 16 ) N / A N / A N / A
(SEGCODE 06 ) 423 8303 5.09 (SEGCODE 17 ) N / A N / A N / A
(SEGCODE 07 ) 0 8369 .00 (SEGCODE 18 ) N / A N / A N / A
(SEGCODE 08 ) 0 5561 .00 (SEGCODE 19 ) N / A N / A N / A
(SEGCODE 09 ) N / A N / A N / A (SEGCODE 20 ) N / A N / A N / A
(SEGCODE 10 ) N / A N / A N / A (SEGCODE 21 ) N / A N / A N / A
(SEGCODE 11 ) N / A N / A N / A (SEGCODE 22 ) N / A N / A N / A
(SEGCODE 12 ) N / A N / A N / A (SEGCODE 23 ) N / A N / A N / A
(SEGCODE 24+) N / A N / A N / A
------------- ---------- ---------- ---------- ------------- ---------- ---------- ----------
#DEPS IN THE DS 3745 55976 6.69First portion of the report
The report fields are as follows:
- DBNAME DB# PARTNAME PART ID REORG# DSG# DDNAME DSNAME DBORG
- The name of the DBD, the database number (in hexadecimal), the name of the partition, partition id, partition reorganization number, the data set group number (in hexadecimal) or the data set group ID (in an alphabetic character), the ddname of this data set group, the name of the data set, and the organization type of the data set
- MAXIMUM ROOTS PER BLOCK
- The maximum number of root segments contained in one Block (OSAM DB) or CI (VSAM DB)
- BLOCKS WITHOUT ROOT SEGMENTS IN RAA
- The number of blocks that do not have root segments in the root addressable area (RAA)
DISTRIBUTION OF ROOT SEGMENTS (HDAM/PHDAM ONLY)
This part shows how the HDAM or PHDAM roots were distributed relative to their home block. If the distribution of the root segment part is requested with the OPTION HOMECHK=(YES,-nnn,+mmm) option in the PROCCTL statement, HD Pointer Checker generates it. If the database is PHDAM, HD Pointer Checker generates the part for each partition.
Note: When the prefix and data parts of an HDAM or a PHDAM root segment are separated, HD Pointer Checker uses the block that contains the data part as its
location.
- LOCATION
- The block location, relative to the home block, where the root segment was found. The locations, within -200 to +200 block to the home block, are indicated by every one block. The locations, relatively lower than -200 and upper than +200 to the home block, are indicated by every 100 blocks.
- NUMBER OF ROOTS
- The number of roots that were placed within the associated relative block
- PERCENTAGE
- The percentage of roots that were placed within the associated relative block
- TOTAL NUMBER OF ROOT SEGMENTS
- The total number of root segments, and the total percentage of root segments (always 100.0%)
- NUMBER OF ROOT SEGMENTS IN HOME BLOCKS
- The number of root segments that are stored in the same blocks as they are assigned by the randomizing routine, and what percentage it makes of the total number of root segments
- NUMBER OF ROOT SEGMENTS NOT IN HOME BLOCKS
- The number of root segments that are not stored in the same blocks as they are assigned by the randomizing routine, and what percentage it makes of the total number of root segments
DISTRIBUTION OF RAP CHAIN LENGTHS (HDAM/PHDAM ONLY)
This part shows how long and how distributed the HDAM or PHDAM RAP chains are. HD Pointer Checker generates this part if so requested by the REPORT
CHAINDIST option in the PROCCTL statement.
- CHAIN LENGTH
- The number of roots that were randomized to a particular RAP. A chain length of 1 means the number of roots that has no synonym root.
- NUMBER OF RAPS
- The number of RAPs that have this chain length
- NUMBER OF ROOTS
- The total number of roots involved in this chain length
- PERCENTAGE OF ROOTS
- The percentage of the total number of roots involved in this chain length
- CUMULATIVE OF PERCENTAGE
- The cumulated value of PERCENTAGE OF ROOTS
- RAPS USED (ACTIVE)
- The number of RAPS one or more of whose roots are randomized
- RAPS NOT USED
- The number of RAPS whose roots are not randomized
- TOTAL RAPS
- The total number of roots in this HDAM database or PHIDAM partition
- MAXIMUM ROOTS PER RAP
- The maximum number of the chain length. If the number exceeds 254, it is displayed as 255+.
- AVERAGE ROOTS PER ACTIVE RAP
- The average number of roots per RAP that is active
- AVERAGE ROOT PER TOTAL RAP
- The average number of roots per total RAPs
- NUMBER OF SYNONYM CHAINS
- The total number of synonym chains. The number of chains whose length is one is not included.
- AVERAGE ROOTS PER SYNONYM CHAINS
- The total number of synonym roots for synonym chains divided by the total number of synonym chains. Neither the number of roots nor the number of chains whose length is one is included.
SUMMARY OF DEPENDENT SEGMENTS DISTRIBUTION
This part shows the summary of dependent segments distribution.
- NUMBER OF DEPENDENTS IN AS SAME BLOCK AS ROOT
- The number of dependent segment occurrences that are in the same block as root segment occurrence
- AVERAGE DEPS IN AS SAME BLOCK AS ROOT PER ROOT
- The average number of dependent segment occurrences that are in the same block as root segment occurrence
- NUMBER OF DEPENDENTS IN THE DIFFERENT BLOCK TO ROOT
- The number of dependent segment occurrences that locate in a different block from root segment occurrence
- DISTRIBUTION OF DEPENDENT SEGMENTS IN ROOT BLOCK
- This part shows the number of root segments that have exactly 0, 1, ..., 23, or 24+ dependent segments in the same block. It also shows the total number of root segments in this data set group or partition.
- DISTRIBUTION OF DEPENDENT SEGMENTS BY SEGMENT CODE
- This part shows the number of dependent segments with segment
code 2, 3, ..., 23, or 24+ that are stored in the same block as their
root segment. It also shows the number of dependent segments with
segment code 2, 3, ..., 23, or 24+ in this data set group or partition.
The following three fields are headings for DISTRIBUTION OF DEPENDENT SEGMENTS BY SEGMENT CODE:
- #DEPS IN ROOT BLOCK
- The number of dependent segments in the root block in which the segments exist
- #DEPS IN ALL BLOCKS
- The number of dependent segments in all blocks
- PERCENTAGE (ROOT/ALL)
- The percentage of the above values; #DEPS IN ROOT BLOCK to #DEPS IN ALL BLOCKS
This part also shows the total number of dependent segments in this data set group.